Cloth supermarket bags may be fashionable, but they can also prove deadly, according to a recent research paper published by the University of Pennsylvania Law School. The researchers point out that after the city of San Francisco banned plastic bags, the number of emergency room visits for bacterial related diseases increased significantly. A Reason.com blog post explains the connection:
Basically people were schlepping leaky packages of meat and other foods in their canvas bags, then wadding to the bags somewhere for awhile, leaving bacteria to grow until the next trip, when they tossed celery or other foods likely to be eaten raw in the same bags.It is in fact plausible that at least some portion of these illnesses did in fact result from reusable bags. Another study conducted by researchers at the University of Arizona and Loma Linda University in 2010 measured bacteria in a sample of reusable bags, finding many containing dangerous bacteria, such as coliform (found in half the bags) and E. coli (found in 12 percent of bags). They also noted that consumers reported that they rarely wash the bags in an attempt to control the development of such pathogens. That is why I am not so surprised to read this in the University of Pennsylvania report:
We examine emergency room admissions related to these bacteria in the wake of the San Francisco ban. We find that ER visits spiked when the ban went into effect. Relative to other counties, ER admissions increases by at least one fourth, and deaths exhibit a similar increase.Ironically, plastic bag bans are not even better for the environment. Reusable bags require far more energy and other resources to make. It is not clear they save resources unless they are used many, many times over. For example, a study produced for the Environment Agency in the United Kingdom found that cotton bags would have to be used 103 times before they yielded environmental benefits. But the government study estimated that cotton bags are only used 51 times, making them worse for the environment than plastic. This study did not even consider the energy and water use associated with washing the bags, which increases their environmental impacts and costs. For more details on why plastic bans don’t help the environment, see my paper on the topic. Here is yet another example of how green advice forcing us to substitute one consumer product for another can be dangerous. For other examples, my recent posts on green advice related to BPA and bottled water. The list continues to grow. Image credit: preetamrai on Flickr.